Runway marker light



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atente en. in, -l%

BJMWM i an menu Pennsylvania Application April 30, 1937,- Serial No. 139,917

14 Claims. '(ei. zit-11.2)

My invention relates, generally, to lighting units and, more particularly, to runway marker lights for airports and the like.

The object of my invention, generally-stated, is to provide a runway marker light which shall be of simple and compact construction, economical to manufacture and install .and which shall function to efiectively mark the runway.

A more specific object of my invention is to provide a runway marker light which may be embedded in the runway surface with its upper end exposed in such manner that the unit may be readily relamped without opening it at or below the ground level.

A further object of my invention is to provide a lighting unit of the above character which functions to direct or concentrate the light produced thereby in a vertically narrow z'one extending at a slight angle to the horizontal plane or runway surface.

Another object of the invention is to provide for utilizing, in a unit of this character, a main prismatic lens to concentrate the light in a limited zone above the horizontal plane or runway surface and 'an auxiliary prismatic lens toredirect the concentrated light into certain "areas in the horizontal plane.

These and other objects of the invention will become more apparent from a reading of the following description in conjunction with the drawings, in which:

Figure 1 is an elevational view partly in section of'a lighting unit embodying the principal features of the invention;

Fig. 2 is a View showing typical vertical light distribution curves of the lighting unit of the invention; f Y Fig. 3 is a plan view of the unit through lines III-Ill of Fig. 1, showing the relative positions of the various parts of the unit; and

Fig. 4 is a plan view showing the lens arrangement used in one embodiment of the invention.

In the preferred embodiment of the invention, the unit comprises generally a housinghaving a cover secured thereto by means of a fluid-tight joint in order that the housing may be embedded in the runway or other surface with the joint slightly below ground level. The cover is pro vided with a central opening through which the lamp bulb extends to a point above ground level. A prismatic lens is mounted on top of the cover over the central opening in such manner as to surround the lamp bulb. The lens is protected by a number of radially disposed upstanding fin members of approximately the same height as the lens, and a removable cover plate is attached to the top of the fin members to close the top of the lens. l p

A reflector is mounted beneath the lamp bulb and a second reflector is supported from the cover plate-above the lamp in order to provide for directing substantially all of the light from the lamp through the lens.

The prismatic lens issodesigned that the light produced by the unit is concentrated in a verti cally narrow zone extendingat a slight angle from the horizontal plane or ground surface.

If desired, a plain glass lens, clear or coloredmay be positioned about the prismatic lens to protect it or to both protect-it and produce a colored light. A colored light may also be produced by using a colored prismatic lens. Fur

ther, the plain lens may be replaced by a second prismatic lens, clear or colored, for concentrating the horizontal light distribution into'one or more restricted'areas or zones.

The primary purpose of the foregoing arrange-' ment is to provide a runway marker light that will produce a desired light distribution, and wherein provision is made for easily gaining access to the interior of the housing by simply removing the tcp cover plate, which is above ground .level without necessitating the opening of the housing at-the main joint between the lower and upper parts of the housing which is below the ground level. Referring now to the drawings, the reference character it designates the main housing of the unitwhich is preferably of cast construction and adapted for mounting beneath the ground level, as indicated in a suitable pit or trench.

The socket H for supporting and conducting current to the lamp I2 is supported by the housing on an adjustable bridge l3 in order to provide for adjusting the vertical position of the lamp, and thus vary the position of the light .tends, as shown. 1

In order to provide for obtaining the desired light distribution, a prismatic lens I9 is positioned about the lamp bulb and may be suppbrted by the cover M on the flanged edge 20 of the central opening .or in any other suitable mannor. Agasket 2| is interposed between the bottom of the lens l9 and'the flange to provide a tight joint.

As-shown best in Figs. 1 and 3, the main cover I4 is provided with a plurality of radially-disposed upstanding fin members 22 which serve to protect the lens and permit the wheel of an airplane or other vehicle to pass over the unit withoutdamage thereto. The fin members 22 also The top cover 23 is a solid plate which renders the light source practically invisible from a point directly above the unit, and serves to hold the lens IS in position and to compress the sealing gaskets 2| and 25 when the screws 24 are tightened to secure the cover in place.

In-order to provide for utilizing substantially all of the light produced by the lamp l2, upper and lower reflectors 26' and 21 are provided. The upper reflector 26 may be supported directly above the lamp by means of the removable cover plate 23 to which it is attached by means of a screw 28. The lower reflector 21, which is of the double curvature type, is supported beneath the lamp bulb by the flange 20 on the main cover I. As shown, the reflector is provided with a top flange 29 which rests upon the flange 20.

It is to be understood, however, that these reflec tors may be supported in any other suitable manner.

' approximately 10 degrees gives satisfactory results, although it may be varied, if desired. The path of a number of typical light rays emanating from the light center 3| is shown in Fig. l. The upper reflector 26 and lower portion of the lower reflector 21 are so coordinated that all of the light striking the upper reflector is directed upon the lower portion of the lower reflector and through the lens I?! in a zone slightly above horizontal, as is indicated by the dotted line a. All of the light from the light center which strikes the lower portion of the /lower reflector directly is directed through the lens in a zone partially superimposed on and slightly above the first-mentioned zone, as indicated by the lightweight full line b. The light which strikes the upper portion of the lower reflector 21 is directed through the lens into a zone slightly less above the horizontal than the two aforementioned zones, as indicated by the dash-dot line 0.

- The direct light, as indicated by the heavyweight full line d, is directed through the lens into a 'zone extending from practically horizontal to a point partially superimposed on the aforesaid first and second zones.

. housing and the main cover.

. to moisture.

the light source or lamp l2 and functions to direct the light therefrom in a predetermined manner as described hereinbefore and which are generally referred to in the lighting art as cylinders, globes, envelopes or refractors. It is to be understood that it is the manner in which the globe, lens, refractor or whatever it may be called, functions to control the light which is of v importance and not the particular shape of the globe or lens.

y In order to protect the prismatic lens I!) from dust and rain or breakage, a plain lens 32 of glass or any suitable translucent material may be positioned about lens H! and supported in the same manner. By using a colored lens for this purpose, a light beam of any desired color may be produced.

In the event that it is desired to concentrate the light into one or more restricted horizontal areas or zones, the plain lens 32 may be replaced by a suitable prismatic lens 33 of the type shown in Fig. 4. The lens 33 provides for concentrating the light in two opposite zones, whereas if this ens is not used the light produced by the unit extends in a zone of 360 aboutthe unit. While the lens shown has the prisms on the outer surface thereof, it is to be understood that a lens having the prisms on the inner surface thereof may be used in place thereof to produce the same results.

A typical light distribution curve of theunit is shown in Fig. 2. Curve 34 shows the vertical distribution of light from the unit when a 600- lumen lamp is used, and the curve 35 shows the light distribution for a l000-lumen lamp From an examination of these curves, it will be apparent that the beam produced by the unit, re-

gardless of whether it extends completely about the unit in a 360 zone or is concentrated into one or more restricted horizontal zones, is confined to a vertically narrow zone extending at a slight angle to the ground level. Thus it is apparent that the marker light is practically in visible from a point in the air directly over the light, but that the beam becomes visible to the pilot of an airplane when he approaches the landing field at the proper landing angle.

In view of the foregoing description, it will now be apparent that I have provided a runway marker light of sturdy and compact construction-which has many advantages over the type of marker lights used heretofore' The principal advantage of'the marker light of my invention over those of the prior art results from the fact that provision is made for readily gaining access to the interior of the housing without breaking the sealed fluid-tight joint between the The normal location of this joint when the light is installed is beneath the ground level where it is subjected Once the .joint is made, it should not be opened for repair or cleaning of the light, as such continued opening and closing thereof moved which then permits a removal of the lower reflector 21. The lamp l2 may be removed for replacement or cleaning Without the removal of either the lens l9 or reflector 21. Likewise, if an auxiliary lens 32 or 33 is used, it may be till are-acct readily removed for cleaning after the cover plate it is lifted. Therefore, it is seen that the unit may be completely serviced without requiring its removal from the pit or trench in which it is mounted. or requiring that any main fluidtight joint be broken.

Although I have described a specific embodiment of my invention, it will be obvious to those skilled in the art that various changes may be made in the details or construction such as in the proportion and the design of the several cooperating parts without departing from the principles herein set forth and defined by the appended claims.

ll claim as my invention:

1. A runway marker light comprising a metal housing adapted to be mounted below the runway surface, a main metal cover member for the housing secured to the upper edge thereof by means of a fluid-tight joint, said cover member having a central opening therein and a plurality of spaced upstanding members surrounding the opening and extending radially therefrom, a

, lamp mounted within the housing and extending upwardly through the central opening in the cover member, a prismatic lens disposed in surrounding relation to the lamp and supported by the cover member over said opening, a plain lens surrounding the prismatic lens and supported by the cover member, and a metal cover plate for the lens detachably secured to the spaced upstanding members and adapted to engage the upper edge of the plain lens and press the lower edge of said plain lens into engagement with the top of the cover member, thereby to entirely enclose the said prismatic lens.

2. A runway marker light comprising a metal housing adapted to be mounted below'the runway suriace, a main metal cover member for the housing secured to the upper edge thereof by means of a fluid-tight joint, said cover memher having a central opening therein and a plurality of spaced upstanding members surrounding the opening and extending radially there from, a lamp mounted within the housing and extending upwardly through the central opening in the cover member, a generally cylindrical prismatic lens supported by the cover member over said central opening, a generally cylindrical plain lens surrounding the prismatic lens, a reflector disposed beneath the lamp and supported by the cover member, a metal cover plate for the lens detachably secured to the spaced upstandin'g members on the main, cover member, and a second reflector secured to said cover plate above the lamp.

3. A runway marker light comprising a metal housing adapted to be mounted below the runway suriace, a main metal cover member for the housing secured to the upper edge thereof by means of a fluid-tight joint, said cover member having a central opening therein and a plurality of spaced upstanding members surrounding the opening, a lamp mounted within the housing and extending upwardly through the central opening in the cover member, a prismatic lens supported by the cover member over said opening in surrounding relation to the lamp, a lower reflector mounted beneath the lamp for reflecte ing light through the lens, a metal cover plate for the lens detachably secured to the spaced upstanding members on the cover member of the housing, an upper reflector attached to the cover plate above the lamp for directing the upward light from the lamp upon the lower reflector whereby substantially all of the light will be utilized, and a second prismatic lens positioned about said first lens for concentrating the horizontal light distribution into one or more predetermined restricted areas.

4. A runway marker light comprising a bowlshaped metal housing member adapted to be mounted below the surface of the runway, a main metal cover member for the housing having a central opening therein, a lamp mounted in the housing and extending upwardly through the opening in the cover member, a prismatic lens surrounding the lamp and supported by the cover member, a plain protective lens for the prismatic lens supported by the cover member, and a metal cover member for the top of the lens and protectlvelens detachably secured to the cover member of the housing.

5. In a runway marker light, in combination, a bowl-shaped ,metal housing member adapted to be mounted below the surface of the runway, a

main metal cover member for the housing having a central opening and a plurality of upstanding spaced members thereon, said cover member being detachably secured to the upper edge of the housing by means of a fluid-tight joint, a lamp supported from within the housing in a vertical position with a portion of bulb extending upwardly through the central opening in the cover member, a prismatic lens disposed in surrounding relation about the exposed end of the bulb and resting upon the edge of the opening in the cover member, a plain lens supported by the cover member in concentric relation with the prismatip lens, and a metal plate member disposed above the top edges of the prismatic lens and plain lens and detachably secured t6 the said spaced upstanding members of the cover member.

6. A runway marker light comprising a metal housing member comprising upper and lower sections joined together by means of a fluidtight joint, said lower section being adapted to be set into the runway surface, a lamp supported within the housing, a prismatic lens disposed in surrounding relation to the lamp and supported by the upper section of the housing, a ringshaped transparentprotective member for the lens supported by the upper section of the housing and a removable cover plate attached t9 the top of the upper section of the housing.

housing member having upper and lower sections joined together by means of a fluid-tight joint, said lowerv section being adapted to be set into the runway surface, a lamp supported within the housing, a prismatic lens disposed in surrounding relation to the lamp and supported by the upper section of the housing above the surface of therunway, a bowl-shaped reflector supported from the upper section beneath the lamp, a removable metal cover plate attached to the top of the upper section, and a second bowl-shaped reflector supported from the cover plate directly over the lamp.

8. A runway marker light comprising a metal housing member comprising upper and lower secllll 7. A runway marker light comprising a metal iii) . 9. A runway marker light comprising a metal housing adapted to be set into the runway surface and provided with a top opening, a lamp mounted in the housing, a prismatic lens for prismatic lens mounted at the top of the housing I and surrounding the lamp, a generally ringshaped member of transparent material surrounding said lens, and a removable cover for the top opening in the housing, said cover including a removable plate providing access to the lamp.

11. A runway marker light comprising a bowlshaped metalhousing member, a main metal cover member for the housing having a central opening and a plurality ofupstanding spaced members thereon, said main cover member being detachably secured to the upper edge of the housing by'means of a fluid-tight joint, a lamp supported from within the housing in a vertical position witha portion of the bulb extending upwardly through the central opening in the main cover member, a sleeve-like prismatic lens. dis-- posed about the exposed end of the lamp bulb and resting upon the edge of the opening in the main cover member, a sleeve-like plain lens of translucent material disposed about the prismatic lens and also resting upon the main cover member, and a removable cover plate secured to the spaced upstanding members of the main cover plate-above the said lens and plain lens of translucent -material.-

12. A runway marker light comprising a bowlshaped metal housing member adapted to be set into the surface of the runway, a main metal cover plate 'for the housing having a central opening provided with an inwardly extending flange and a plurality .of spaced upstanding radial members disposed about the central opening; said main metal cover plate being secured to the'upper edge'of the housing by means of a fluidtight joint, a lamp supported from within the housing and extending upwardly through the central opening in the main cover plate, a prismatic lens disposed about the upper end of the lamp bulb and supported by the inwardly extending flange on the main cover plate, a generally ring-shaped protective member of translucent material supported by the said flange in concentric relation about the lens, a reflector mounted beneath the lamp bulb and supported from said flange, and a metal cover plate for the lens and protective member detachably secured to the spaced upstanding radial members main cover member, a prismatic lens mounted at the top of thehousingadjacent' the light source and supported by the main cover member to extend upwardly above the'runway surface for concentrating the light from the source in a. vertically narrow zone extending at a slight angle to the horizontal and a detachable cover plate for the prismatic lens supported by the spaced upstanding members on the main cover member above the prismatic lens.

14. A runway marker light comprising a metal housing adapted to be set into the surface of the runway,'a main metal cover member for the housing joined thereto by a fluid-tight joint that may be positioned at or belowthe runway surface, said main cover member having a central opening therein surrounded by spaced upstanding guard members extending radially-therefrom,

a lamp mounted within the housing and extending upwardly through the central opening in the main cover member, a prismatic lens supported by the main cover member adjacent to said lamp above the runway surface for controlling the light distribution of the lamp to produce a vertically narrow beam of light extending ata predetermined angle of less than ninety degrees to the horizontaL'a bowl-shaped reflector supported by the main cover member below the light source in the lamp to increase the intensity of the beam and a cover member for the housing detachably secured to the spaced upstanding guard members above the prismatic lens.

WILLIS A. PENNOW. 

